That epoxy resin is good stuff, we used it on rotten wooden sills, 'til we got new windows and just ripped all the old stuff out and installed new wood all around.
I think installing the weatherstripping on the frame is a good idea, and it should be a little simpler, too.
Heh....I've got a plan then. I just need to finish the glazing project and find some epoxy resin. How long does it take for that stuff to cure?